I've been taking this product for several months. It has definitely helped during times when I've been mentally unfocused. I've actually seen an increase in my attention span while working with difficult tasks at work (I read a lot of scientific articles and review data). I would have to say that my perception of increased mental clarity is real.

I've tried many brands of Vitamin C, and this one has become my favorite buffered C. Obvious rapid assimilation, no harshness on the stomach. Price is unbeatable compared to other buffered or ester Cs.